• Title/Summary/Keyword: korean peninsula

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The Gradient Analysis of the Korean Peninsula by using DEM (DEM을 이용한 한반도 지형의 경사도 분석)

  • Lee, Kum-Sam;Jo, Wha-Ryong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.3 no.1
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    • pp.35-43
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    • 2000
  • The slope gradient of the Korean Peninsula was analyzed by using DEM(DTED level 1). The Peninsula has high percentages of gentle slopes. But low plains and very steep slope regions are scarcely distributed in the Peninsula. Altitude lower than 150m areas are composed of plains and undulated plains. The steepest and most rugged topographies are observed in the range of altitude from 500m to 1,000m areas. The areas of altitude greater than 1,000m show plateau landscapes. By overlapping digital geology maps and the gradient grade maps, We revealed the characteristics of slope regions by geological districts. High latitude with steep slope are well developed in the geological districts of granitic gneiss(ARgr) and gneiss($PR_1$) of the Pre-Cambrian, sandstone of the Paleozoic era(P-T), and sedimentary rocks of the Mesozoic era($J_2$). Low altitude with gentle slope areas are representative in the districts of granite of the Mesozoic era($Jgr_1$), the Cretaceous sedimentary rocks of the Mesozoic era($K_1$, $K_2$) and the Cenozoic strata(N). Basalt extruded the Quaternary($Q_1$) are observed in the areas of very gentle slope but greater than 1,000m altitude.

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Characteristic Analysis of Multicell Convective System that Occurred on 6 August 2013 over the Korean Peninsula (2013년 8월 6일 한반도에서 발달한 다세포(Multicell) 대류계의 특성 분석)

  • Yoon, Ji-Hyun;Min, Ki-Hong
    • Atmosphere
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    • v.26 no.2
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    • pp.321-336
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    • 2016
  • Damages caused by torrential rain occur every year in Korea and summer time convection can cause strong thunderstorms to develop which bring dangerous weather such as torrential rain, gusts, and flash flooding. On 6 August 2013 a sudden torrential rain concentrated over the inland of Southern Korean Peninsula occurred. This was an event characterized as a mesoscale multicellular convection. The purpose of this study is to analyze the conditions of the multicellular convection and the synoptic and mesoscale nature of the system development. To this end, dynamical and thermodynamic analyses of surface and upper-level weather charts, satellite images, soundings, reanalysis data and WRF model simulations are performed. At the beginning stage there was a cool, dry air intrusion in the upper-level of the Korean Peninsula, and a warm humid air flow from the southwest in the lower-level creating atmospheric instability. This produced a single cell cumulonimbus cloud in the vicinity of Baengnyeongdo, and due to baroclinic instability, shear and cyclonic vorticity the cloud further developed into a multicellular convection. The cloud system moved southeast towards Seoul metropolitan area accompanied by lightning, heavy precipitation and strong wind gusts. In addition, atmospheric instability due to daytime insolation caused new convective cells to develop in the upstream part of the Sobaek Mountain which merged with existing multicellular convection creating a larger system. This case was unusual because the system was affected little by the upper-level jet stream which is typical in Korea. The development and propagation of the multicellular convection showed strong mesoscale characteristics and was not governed by large synoptic-scale dynamics. In particular, the system moved southeast crossing the Peninsula diagonally from northwest to southeast and did not follow the upper-level westerly pattern. The analysis result shows that the movement of the system can be determined by the vertical wind shear.

The influence of Chinese multi-polarization strategy on the security of Korean peninsula (중국의 다극화 전략이 한반도 안보에 미치는 영향)

  • Choe, Gyeong-Sik
    • Journal of National Security and Military Science
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    • s.4
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    • pp.241-287
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    • 2006
  • 16th CPC National Party Congress established multi-polarization strategy as an external strategy, and 'The Great Reinvigoration of Chinese Nation' as the aim of The Great Strategy of China. It is required to maintain stabilized and peaceful surrounding circumstance in order to make it possible. The ideal surrounding circumstance that China is aiming for is to achieve multi-polarization of international society while maintaining strategic deterrence. Multi-polarization now in 'One super Multi powers' is that 'Multi powers' deter 'One super' to prevent predominance of USA and to decentralize the power. China wishes to realign international order as it accomplishes multi-polarization. China who wants 'Peace and Stabilization' emphasizes autonomy, peace and unification of Korean peninsula. Autonomy means the restraint intervention of foreign power, that is, American influence in Korean peninsula. Multi-polarization strategy of China will be used in Korean peninsula to solve nuclear issue of North Korea, to support neutral unification and to keep balance of power with USA, Japan and Russia as it renders economic advantages to South Korea and security engagement to North Korea, based on special geographical, cultural and historical relationship with two Koreas. The nuclear issue of North Korea will be a stage to test multi-polarization of China. When it deduces positive solution of nuclear issue due to successful six-party talks, and advances to security talks of Northeast Asia, it will contribute a lot to power and elevation of national stature of China in international society. Thus, the Chinese strategy will be an accommodative condition for the security of South Korea, and it requires wise decision of South Korea to make hay while the sun shine.

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Lightning activity in summer monsoon precipitation over Korean peninsula

  • Kar, S.K.;Ha, Kyung-Ja
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.366-366
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    • 2002
  • Cloud-to ground lightning and total precipitation over Korean peninsula during the summer monsoon season are studied extensively with a special emphasis on the characteristics of convective precipitation. Ten years (1988-1997) lightning and rainfall data and a temporal and spatial scale of one month and 10$^2$ km$^2$ respectively are used to calculate the monthly number of CG lightning flash count. Monsoonal convective activity is higher over the west coast with maxima at two different regions, one in the northern part which increases nortwestward and the other is at the middle west coast of Korea increasing towards the west coast. East coast represents the minimum value of monsoonal convective activity. In the east coast of Korean peninsula, particularly in the region east of Tae-back mountain, the value of Rain yield, (which is defined as the ratio of total precipitation to CG flash count over a common area), is maximum with an average value of 3$\times$10$^{8}$ kg fl$^{-1}$, while the minimum value of rain yield is occurred in the west of Tae-back mountain, with an average value of 0.8$\times$10$^{8}$ kg fl$^{-1}$. Results show in the west coast stations, nearly 82% of the total rainfall is convective in nature, at the middle of the peninsula 53% of the total rain is convective while in the east coast stations 46% contribution from the convective rain is seen. Kanghwa receives the maximum convective rain while at Ulsan the convective rain is minimum. Correlation coefficient between the total precipitation and CG lightning during the summer monsoon season is 0.54.

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Evaluation of the Gap Filler Radar as an Implementation of the 1.5 km CAPPI Data in Korea (국내 1.5 km CAPPI 자료 보완을 위한 Gap Filler Radar의 효용성 평가)

  • Yoo, Chulsang;Yoon, Jungsoo;Kim, Jungho;Ro, Yonghun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.521-521
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    • 2015
  • This study evaluated the gap filler radar as an implementation of the 1.5 km CAPPI data in Korea. The use of the 1.5 km CAPPI data was an inevitable choice, given the topography of the Korean Peninsula and the location of the radar. However, there still exists a significant portion of beam blockage, and thus there has been debate about the need to introduce the gap filler radar (or, the gap-filler). This study evaluated the possible benefits of introducing gap-fillers over the Korean Peninsula. As a first step, the error of the radar data was quantified by the G/R ratio and RMSE, and the radar data over the Korean Peninsula were evaluated. Then, the gap-fillers were located where the error was high, whose effect was then evaluated by the decrease in the G/R ratio and RMSE. The results show that the mean values of the G/R ratio and RMSE of the 1.5 m CAPPI data over the Korean Peninsula were estimated to be about 2.5 and 4.5 mm/hr, respectively. Even after the mean-field bias correction, the RMSE of the 1.5 km CAPPI data has not decreased much to be remained very high around 4.4 mm/hr. Unfortunately, the effect of the gap-filler on the 1.5 CAPPI data was also found very small, just 1 - 2%. However, the gap-filler could be beneficial, if the lowest elevation angle data were used instead of the 1.5 km CAPPI data. The effect of five gap-fillers could be up to 7% decrease in RMSE.

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Historic plant specimens collected from the Korean Peninsula in the early 20th century (I) (20세기 초에 채집된 한반도 고표본 (I))

  • Im, Hyoung-Tak;Son, Hyun-Duk;Im, Jae-Suk
    • Korean Journal of Plant Taxonomy
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    • v.46 no.1
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    • pp.33-54
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    • 2016
  • Many of the historic plant specimens collected from the Korean Peninsula in the early 20th century deposited in herbaria in Korea were destroyed during the Korean War. However, duplicates of the specimens deposited in the Herbarium of the University of Tokyo (TI) remained unharmed. We examined historic plant specimens, identified undetermined specimens, and made a list to provide fundamental information on the early taxonomic history of Korea. One set of duplicate specimens was donated by TI and deposited into the Chonnam National University herbarium (CNU) and into the herbarium of the National Institute of Biological Resources in Korea (KB).

A Review of Recent Climate Trends and Causes over the Korean Peninsula (한반도 기후변화의 추세와 원인 고찰)

  • An, Soon-Il;Ha, Kyung-Ja;Seo, Kyong-Hwan;Yeh, Sang-Wook;Min, Seung-Ki;Ho, Chang-Hoi
    • Journal of Climate Change Research
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    • v.2 no.4
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    • pp.237-251
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    • 2011
  • This study presents a review on the recent climate change over the Korean peninsula, which has experienced a significant change due to the human-induced global warming more strongly than other regions. The recent measurement of carbon dioxide concentrations over the Korean peninsula shows a faster rise than the global average, and the increasing trend in surface temperature over this region is much larger than the global mean trend. Recent observational studies reporting the weakened cold extremes and intensified warm extremes over the region support consistently the increase of mean temperature. Surface vegetation greenness in spring has also progressed relatively more quickly. Summer precipitation over the Korean peninsula has increased by about 15% since 1990 compared to the previous period. This was mainly due to an increase in August. On the other hand, a slight decrease in the precipitation (about 5%) during Changma period (rainy season of the East Asian summer monsoon), was observed. The heavy rainfall amounts exhibit an increasing trend particularly since the late 1970s, and a consecutive dry-day has also increased primarily over the southern area. This indicates that the duration of precipitation events has shortened, while their intensity became stronger. During the past decades, there have been more stronger typhoons affecting the Korean peninsula with landing more preferentially over the southeastern area. Meanwhile, the urbanization effect is likely to contribute to the rapid warming, explaining about 28% of total temperature increase during the past 55 years. The impact of El Nino on seasonal climate over the Korean peninsula has been well established - winter [summer] temperatures was generally higher [lower] than normal, and summer rainfall tends to increase during El-Nino years. It is suggested that more frequent occurrence of the 'central-Pacific El-Nino' during recent decades may have induced warmer summer and fall over the Korean peninsula. In short, detection and attribution studies provided fundamental information that needed to construct more reliable projections of future climate changes, and therefore more comprehensive researches are required for better understanding of past climate variations.

The study of Reversed Two Station Method on Korea-Japan Seismic Data to Obtain Lg Attenuation of Korean Peninsula (한반도 Lg파 감쇠상수 도출을 위한 한일 지진자료의 RTSM 적용에 대한 연구)

  • Chung, Tae-Woong
    • Geophysics and Geophysical Exploration
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    • v.11 no.4
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    • pp.310-317
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    • 2008
  • Lg amplitude decrease $Q^{-1}$ is very important because the Lg phase is the largest seismic phase in Korea if hazardous earthquakes occurred at neighbor nations such as Japan and China. Since reliable $Q^{-1}$ from two station method can be obtained by long pair distance of stations or events, we used seismic stations both Korea and Japans recording Korean events. The obtained $Q^{-1}$ values, however, were anomalously high; these misguided values, inconsistent with tectonic activity of Korean Peninsula, seems to be related with high $Q^{-1}$ values of Japan region.

A Study of Long-term Change in Carbon Dioxide Concentrations within and Across the Korean Peninsula between 1996 and 1997 (국내외 관측점간의 비교분석을 통한 이산화탄소의 장주기적 농도변화 특성에 관한)

  • 김기현;윤용훈;송기범
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.1
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    • pp.105-115
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    • 2001
  • This study was conducted to analyzed the pattern of $CO_2$ concentration changes in various time scale within and across the Korean Peninsula. We compared that data sets obtained from Moo-Ahn(NAN) station in Korea with those determined from major background observatory stations around the world from the periods of Aug. 1995 to Dec. 1997. The mean $CO_2$concentrations of the MAN area, if computed using the total of 884 daily mean values, were computed to by 374.5$\pm$6.6 ppm. When the background data for MAN were compared with those of other background site, the concentration of MAN was systematically higher than any other comparable sites. Results of correlation analysis between MAN and other background sites generally showed up the existence of strong correlations, indicating that the relative effect of $CO_2$ concentration change can proceed similarly over the globe. However, notable differences in annual growth rate of $CO_2$ between MAN and all the comparative sites suggested that its concentration in th MAN area be regulated in more complicated manners than those in the other areas. It is thus suspected that the data collected form MAN area be not effective enough to represent areal distribution characteristics of $CO_2$in the Korean Peninsula.

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Some Characteristics of Seismicity and Stress State in the Korean Peninsula Using the Korean Seismic Data of the Past and the Present (과거 및 현재 지진 Data로부터 한반도 지진활동과 응력 상태)

  • 오충량;김소구;고복춘
    • The Journal of Engineering Geology
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    • v.5 no.3
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    • pp.309-329
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    • 1995
  • Seismicity and stress state in the Korean peninsula are studied using the catalogue of historical earthquakes and that from the seismological observations before the 1960s, with the aid of instrumental catalogue up to 1995. It seems that the completeness of the historical catalogue has a significant enhancement during the first two hundred years of the Yi dynasty, i.e., from the 1400s to the 1600s. From then on the catalogue may be regarded as near to complete for strong earthquakes in an overall sense. From the distribution of strong earthquakes, three seismic zones may be identified. From the south to the north, those are the southern seismic zone (남부지진대), the Seoul-Pyongyang seismic zone (서울-평양지진대), and the northern seismic zone (북부지진대). The mechanisms of some earthquakes obtained using first motion read- ings are reevaluated with a grid testing method. The results indicate that the compressional axis is nearly horizontal along the EW direction.

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